So I came across these specific delusions, called "monothematic"

* Capgras delusion is the belief that (usually) a close relative or spouse has been replaced by an identical-looking impostor.
* Fregoli delusion is the belief that various people that the believer meets are actually the same person in disguise.
* Intermetamorphosis is the belief that people in the environment swap identities with each other whilst maintaining the same appearance.
* Subjective doubles, in which a person believes there is a doppelgänger or double of him or herself carrying out independent actions.
* Cotard delusion is the belief that oneself is dead or does not exist; sometimes coupled with the belief that they are putrifying or missing their internal organs.
* Mirrored self-misidentification is the belief that one's reflection in a mirror is some other person.
* Reduplicative paramnesia is the belief that a familiar person, place, object or body part has been duplicated. For example, a person may believe that they are in fact not in the hospital to which they were admitted, but an identical-looking hospital in a different part of the country.
* Somatoparaphrenia is the delusion where one denies ownership of a limb or an entire side of ones body (often connected with stroke).

Note that some of these delusions are also sometimes grouped under the umbrella term of delusional misidentification syndrome.


I found these to be very entertaining.